Comment 5 for bug 1575815

I didn't run into any issue with dhclient. I did the following with the failing interface:

root@saiph:~# dhclient eth0
RTNETLINK answers: File exists
root@saiph:~# ifdown eth0
ifdown: interface eth0 not configured
root@saiph:~# dhclient eth0
RTNETLINK answers: File exists
root@saiph:~# ifup eth0
Internet Systems Consortium DHCP Client 4.2.4
Copyright 2004-2012 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/60:eb:69:dc:3e:19
Sending on LPF/eth0/60:eb:69:dc:3e:19
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3 (xid=0xbe2a1700)
DHCPREQUEST of 10.244.192.169 on eth0 to 255.255.255.255 port 67 (xid=0x172abe)
DHCPOFFER of 10.244.192.169 from 10.244.192.10
DHCPACK of 10.244.192.169 from 10.244.192.10
RTNETLINK answers: File exists
bound to 10.244.192.169 -- renewal in 17523 seconds.
root@saiph:~# ifdown eth0
Internet Systems Consortium DHCP Client 4.2.4
Copyright 2004-2012 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/60:eb:69:dc:3e:19
Sending on LPF/eth0/60:eb:69:dc:3e:19
Sending on Socket/fallback
DHCPRELEASE on eth0 to 10.244.192.10 port 67 (xid=0x5f632f4c)
root@saiph:~# dhclient eth0
root@saiph:~# ifconfig
eth0 Link encap:Ethernet HWaddr 60:eb:69:dc:3e:19
          inet addr:10.244.192.169 Bcast:10.244.255.255 Mask:255.255.192.0
          inet6 addr: fe80::62eb:69ff:fedc:3e19/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:57 errors:0 dropped:0 overruns:0 frame:0
          TX packets:9 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:5257 (5.2 KB) TX bytes:1026 (1.0 KB)

eth1 Link encap:Ethernet HWaddr 60:eb:69:dc:3e:1a
          inet addr:10.244.240.12 Bcast:10.244.255.255 Mask:255.255.192.0
          inet6 addr: fe80::62eb:69ff:fedc:3e1a/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:3960 errors:0 dropped:0 overruns:0 frame:0
          TX packets:379 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:306067 (306.0 KB) TX bytes:51176 (51.1 KB)

lo Link encap:Local Loopback
          inet addr:127.0.0.1 Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING MTU:65536 Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)